
public class CalculatorLogic {
// Instance variables.
private int _currentTotal;
// The current total is all we need to remember.
/** Constructor */
public CalculatorLogic() {
_currentTotal = 0;
}
public String getTotalString() {
return "" + _currentTotal;
}
public void setTotal(String n) {
	_currentTotal = convertToNumber(n);
	}
	public void add(String n) {
	_currentTotal += convertToNumber(n);
	}
	public void subtract(String n) {
	_currentTotal -= convertToNumber(n);
	}
	public void multiply(String n) {
	_currentTotal *= convertToNumber(n);
	}
	public void divide(String n) {
	_currentTotal /= convertToNumber(n);
	}
	private int convertToNumber(String n) {
	return Integer.parseInt(n);
	}
	}
